The present invention relates to a heat exchange apparatus which is useful for melting sulfur. The present invention when embodied as a steam lance for melting sulfur is especially useful to open the plugged outlet underneath a sulfur tank car containing molten sulfur. Prior to the present invention the plug of solid sulfur in the outlet underneath the sulfur car would be broken or dislogged by the manual use of a metal pick. Such practice was dangerous because once the plug of solidified sulfur melted it could cause the release of additional hot molten sulfur from the body of the outlet.
The invention can comprise a heat exchange apparatus comprising:
(a) tip means for contacting a material to be heated, PA1 (b) conduit means for conducting heat exchanging fluid to, or to and from, said tip means, and PA1 (c) pivot means disposed in an operative relationship therewith for pivotally supporting said conduit means to enable the application of force to said conduit means to urge said tip means against or into said material to be heated.
Although the apparatus is broadly useful for indirect heat exchange between any fluid heat exchange medium and any second material with which heat is to be exchanged to or from said fluid heat exchange medium, the invention is more specifically exemplified by an apparatus (sometimes termed herein a "steam lance") wherein steam is the fluid heat exchange medium.
An especially useful apparatus is a steam lance for melting solidified sulfur, particularly the plug of solid sulfur which commonly forms in the bottom outlet pipe of a railroad tank car or other transporting vehicle containing molten sulfur. Such an apparatus is sometimes termed herein "a sulfur steam lance" or a "sulfur lance".
The sulfur lance apparatus in this embodiment can comprise (a) a steam lance having a conduit means, sometimes hereinafter called a "body means" for containing super heated steam and water or condensate formed upon liquifaction of said steam and for conducting it away from the tip means, (b) a tip means for contact between said body means and the plug of solid sulfur to which heat is to be transfered to effect melting thereof; (c) connecting means to connect the body means to a source of steam and to remove condensate from said body means; (d) directing means (such as a conduit means) within said main body means to direct the steam from the connecting mains through the body means to the tip means and to direct condensate from the tip means through the body means to the connecting mains; and, (e) pivot supporting means attached to the body means to support the weight of the body means, the pivot means being located such that the body means is substantially counterbalanced in order that manual movement of the body portion causes the tip portion to enter a transporting vehicle and melt the solidified sulfur contained therein.
Preferably the tip means is relatively rigid or nonflexible and is disposed at an angle of less than 180.degree. with respect to the main body portion, (i.e., substantially 90.degree.) and further preferred, where the transporting vehicle is a railroad car, the pivot supporting means is attached to means for attaching the apparatus to a railroad rail.
U.S. Pat. No. 4,191,200 to Jagodzinski, et.al, discloses the broad concept of utilizing a steam heating probe to melt a solidified block of sulfur. In this patent, a plurality of such probes are inserted in holes drilled near the bottom of a sulfur storage block to melt the sulfur which is subsequently drawn off for use.
U.S. Pat. No. 4,203,625 of Ellithorpe, et.al, discloses a moveable heating element used to melt a solidified sulfur storage block. This heating element does not utilize a steam heated probe, but does use a counter-weight system to move the heating element into the sulfur block as it melts.
U.S. Pat. No. 752,449 to Greenway, discloses an apparatus which is inserted into a railroad car to thaw out a frozen granular load to facilitate the unloading of the car. This device involves direct heat exchange contact between the steam or other heated fluid and the material to be heated. In contrast, the present invention involves indirect heat exchange between a fluid heat exchange medium and the material which is to be either heated or cooled, (in the case of sulfur, to be heated in order to cause it to melt).
U.S. Pat. No. 4,190,100 to Wallace, U.S. Pat. No. 2,232,272 to Rieger and U.S. Pat. No. 879,745 to Cooper, all show heated probe devices having means to transport the heating fluid, such as steam, to the probe tip and to return the low temperature steam or condensate to the heat source. In Cooper, this is achieved by placing a lateral wall across the hollow probe interior, while Rieger and Wallace utilize concentric tube arrangements. None of these patents, however, teach the use of such a probe to facilitate unloading of a railroad car or other transporting vehicle, nor do any show a prop having its tip oriented at an angle to the remainder of its body.
U.S. Pat. No. 392,844 to Best, discloses a spike-like device which is driven into a frozen load in a railroad car and consequently attached to a steam line. Openings along the steam spike allow the steam to pass into the load and melt or otherwise loosen it.
Super heated compressed air or a stream of water have also been used to reduce the viscosity of a railroad car load to facilitate its unloading. U.S. Pat. No. 3,500,900 to Kupka, shows a plurality of high pressure air nozzles located on a stand on either side of railroad car to project super-heated air into the car and reduce the viscosity of the load contained therein. U.S. Pat. No. 2,830,702 to Hagen, utilizes a nozzle means to direct water into a railroad car to facilitate the removal of grain or other granular substance contained therein.
U.S. Pat. No. 2,095,627 to Burns, discloses a hand manipulated device mounted on a pivoted support adjacent a railroad track for use in holding hoses to spray wash locomotives, railway cars and other relatively large and long objects. U.S. Pat. No. 2,981,484 to Hirsch, shows a hand manipulated steam gun which utilizes a spray of high temperature water or steam for cleaning heavy machinery and vehicles. U.S. Pat. No. 2,234,825 to Koppers shows a hand manipulated pipe for directing steam into a coke oven.